title: Netazepide, a gastrin receptor antagonist, normalises tumour biomarkers and causes regression of type 1 gastric neuroendocrine tumours in a nonrandomised trial of patients with chronic atrophic gastritis.
abstract: BACKGROUND
  Autoimmune chronic atrophic gastritis (CAG) causes hypochlorhydria and hypergastrinaemia, which can lead to enterochromaffin-like (ECL) cell hyperplasia and gastric neuroendocrine tumours (type 1 gastric NETs). Most behave indolently, but some larger tumours metastasise. Antrectomy, which removes the source of the hypergastrinaemia, usually causes tumour regression. Non-clinical and healthy-subject studies have shown that netazepide (YF476) is a potent, highly selective and orally-active gastrin/CCK-2 receptor antagonist. Also, it is effective in animal models of ECL-cell tumours induced by hypergastrinaemia.
  
  
  OBJECTIVE
  To assess the effect of netazepide on tumour biomarkers, number and size in patients with type I gastric NETs.
  
  
  METHODS
  We studied 8 patients with multiple tumours and raised circulating gastrin and chromogranin A (CgA) concentrations in an open trial of oral netazepide for 12 weeks, with follow-up 12 weeks later. At 0, 6, 12 and 24 weeks, we carried out gastroscopy, counted and measured tumours, and took biopsies to assess abundances of several ECL-cell constituents. At 0, 3, 6, 9, 12 and 24 weeks, we measured circulating gastrin and CgA and assessed safety and tolerability.
  
  
  RESULTS
  Netazepide was safe and well tolerated. Abundances of CgA (p<0.05), histidine decarboxylase (p<0.05) and matrix metalloproteinase-7(p<0.10) were reduced at 6 and 12 weeks, but were raised again at follow-up. Likewise, plasma CgA was reduced at 3 weeks (p<0.01), remained so until 12 weeks, but was raised again at follow-up. Tumours were fewer and the size of the largest one was smaller (p<0.05) at 12 weeks, and remained so at follow-up. Serum gastrin was unaffected.
  
  
  CONCLUSIONS
  The reduction in abundances, plasma CgA, and tumour number and size by netazepide show that type 1 NETs are gastrin-dependent tumours. Failure of netazepide to increase serum gastrin further is consistent with achlorhydria. Netazepide is a potential new treatment for type 1 NETs. Longer, controlled trials are justified.
  
  
  BACKGROUND
  European Union EudraCT database 2007-002916-24 https://www.clinicaltrialsregister.eu/ctr-search/search?query=2007-002916-24ClinicalTrials.gov NCT01339169 http://clinicaltrials.gov/ct2/show/NCT01339169?term=yf476&rank=5.
authors.affiliation: Department of Gastroenterology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom ; Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Moore
authors.forename: Malcolm
authors.initials: M
authors.lastname: Boyce
authors.forename: Islay A
authors.initials: IA
authors.lastname: Steele
authors.forename: Fiona
authors.initials: F
authors.lastname: Campbell
authors.forename: Andrea
authors.initials: A
authors.lastname: Varro
authors.forename: D Mark
authors.initials: DM
authors.lastname: Pritchard
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001570:Benzodiazepinones / Q000494:pharmacology / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D001706:Biopsy; D053379:Chromogranin A / Q000097:blood; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism / Q000473:pathology; D005755:Gastrins / Q000097:blood; D005757:Gastritis, Atrophic / Q000150:complications*; D005773:Gastroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000150:complications* / Q000188:drug therapy* / Q000473:pathology; D010671:Phenylurea Compounds / Q000494:pharmacology / Q000627:therapeutic use*; D043887:Receptor, Cholecystokinin B / Q000037:antagonists & inhibitors*; D013274:Stomach Neoplasms / Q000150:complications* / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D000970:Antineoplastic Agents; D001570:Benzodiazepinones; D015415:Biomarkers; D053379:Chromogranin A; D005755:Gastrins; D010671:Phenylurea Compounds; D043887:Receptor, Cholecystokinin B; C104428:YF 476